<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>basic gride</title>
    <style>
        .grid{
            display: flex;
        }

        .grid-cell{
            width: 100px;
            height: 100px;
            margin: 5px;
            background-color: #ccc;
            flex:1;
        }
    </style>
</head>
<body>
    <div class="grid">
        <div class="grid-cell"></div>
        <div class="grid-cell"></div>
        <div class="grid-cell"></div>
    </div>
</body>
</html>